Means for preventing an electric discharge through a gas column.



D. MOP. MOORE. MEANS FOR PREVENTING AN ELECTRIC msomnen THROUGH A GAS 0011111111. APPLICATION FILED APBH], 1906.

1,005,866. Patented 0011111911,

WITNESSES: I men/r00 Daniel m n'rlan moon N1 ED STATES PATENT OFFICE.

DANIEL McFARLAN MOORE, OF NEWARK, NEW JERSEY, ASSIGNOR TO MOORE ELEC- TRICAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

MEANS FOR PREVENTING AN ELECTRIC DISCHARGE THROUGH A GAS COLUMN.

Specification of Letters Patent.

. Patented Oct. 17, 1911.

Application filed April 7, 1906. Serial No. 310,408.

To all whom it may concern:

Be it known that I, DANIEL MCFARLAN MOORE, a citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, with post-office address 52 Lawrence street, have invented certain new and useful Improvements in Means for Preventing an Electric column or body of gas by interposing therein finely divided non-conducting material, either in solid or loose state, but preferably consisting of a mass of granular material. Such granular material when employed in a tube or passage through which air or other gas is fed into or withdrawn from the tube, being pervious to the gas, permits the same to circulate, but being also of an insulating character prevents an electric discharge of .the high potential energy employed across the electric terminals of said tube.

One application of my invention is to a feed tube connected to a vacuum tube so as to feed gas into both ends thereof; the granular or other finely divided material then acts to prevent short-circuiting of the electric energy. Another application is to a tube connected at one terminal only to the vacuum tube and in such case, the granular material operates to prevent escape of the electric energy through said tube to any conductors or body of different potential, as for instance, to a pump employed in exhausting said tube.

The invention may be also applied to a tube having terminals connected to supply wires carrying high potential energy and in such case operates to prevent the escape of energy of the normal tension but will permit the excessive potentials such as lightning discharges to escape from said conductor or wire through the gas column containing said granular or similar material inclosed in a sealed tube.

In the accompanying drawings, Figure 1 is a general plan illustrating the application of my invention to a vacuum tube used forlighting. Fig. 2 shows the same applied to a tube used for exhaustion of the vacuum tube. Fig. 3 shows my invention as embodied in a lightning arrester.

Referring to Fig. 1, wherein I have shown the application of my invention to a vacuum tube lamp, 1 indicates the luminous portion of the tube containing air or other gas. 2 indicates the electrodes or terminal through which electric energy is supplied to the contents of the tube for the purpose of rendering the gas or vapor contents luminous. The energy may be alternating or. continuous and ordinarily is of high p0- tential when metallic vapors are not employed or when, as in my system of lighting, the tube 1 is of great length as compared with its cross section or caliber. I have shown the tube, however, as connected at its terminals to a secondary of a trans former which is shown to typify any source of alternating or intermittent currents. The electrodes 2 are shown as internal electrodes located within enlarged terminals of the tube 1, but they might be external electrodes. 6 indicates a tube through which air or other gas or vapor may be fed into or withdrawn from the tube 1. Said tube 6 is connected to the tube 1 bybranches 6 and at points of said tube near to the terminals so that the length of the path for the electric energy passing from one terminal 2 to the other through the passages 6' will necessarily be short as compared with the length of the path through the tube 1 when the same is made of any considerable length.

.Under these conditions, there is a tendency to a diversion or short-circuiting of the electric energy through the tube 6' or such energy may even, under defective conditions of installation pass through or be diverted through the tube 6-to other metallic conductors or to ground. To avoid this, a mass of material 24 pervious to gas is located in the passages through which the energy may tend to be short-circuited or diverted. Such material may be located wholly in the tube-6 or may extend into the tube 6. Such material may be solid or loose and sub-divided mechanically, but, generally speaking, should be of an insulating character. It is convenient ordinarily to use a mass of granular material and in practice fine beach sand will be found to be suitable, the said sand being held in position in any suitable way, such as providing some fibrous packing in the tube such as a mass of glass fabric. This material is pervious to the air, gas or vapor passing into or from the tube 1, but will act to prevent the shortcircuiting of the energy and will avoid the possibility of the high potential applied to the tube working back through tube 6 to any conducting material with which said tube is connected.

It is obvious that the invention is not limited to tubes 6, 6 connected to a vacuum tube near the ends thereof or in a manner to bridge portions of said tube across which the high difference of potential exists.

In Fig. 2 the tube 6 is shown connected at one point only to the tube 1, and is shown joined to a pump 7 driven from an electric motor 8. Said motor may be supplied with energy from ordinary 110 volt mains. Any tendency of electric energy in the tube 1 to work back into tube 6 and the pump or motor can be eifectually prevented by the interposition of beach sand 24 or other suitable material which will permit circulation of the gas or air being exhausted from the tube or being fed into the same. 9 is a bypass around the section of tube 6 containing the porous material which serves to permit the air or gas to circulate freely when the stop-cock 10 in said by-pass is opened. Said by-pass is employed when no or little energy is being applied to the tube, as for instance, during the first stages of the process of exhausting the tube and is useful in avoiding the delay which would be met with if it were necessary to carry on the whole process of exhausting through the porous material which, obviously, will not allow free circulation when it is desired to carry on the operation rapidly, although, it will permit sufiicient circulation when the last stages of exhaustion are reached or when it is permissible to pass the gas through the tube 6 in either direction at a slow rate.

Referring to Fig. 3, my invention is shown as applied in a device operatingas a lightning arrester. Electric mains or con-' ductors carrying energy are indicated at 11. In a ground connection from one of them or in any connection through which it is desired to permit the passage momentarily of excessive high potentials existing on a main 11 is interposed a tube of any desired material 1 containing sand or other porous material as hereinbefore described. At the terminals of the tube are electrodes 2, sealed therein and connected respectively to the conductor 11 and to the ground or other point forming the opposite pole of the ex: cessive discharge circuit. Conveniently, the tube 1 is of glass and electrodes 2 are sealed therein air-tight. The tube is exhausted bfthat under ordinary conditions the energy of the main 11 will not pass to earth. Excessively high potentials may, however, find an escape through the tenuous gas or vapor.

What I claim as my invention is:

1. A tube containing air or gas under reduced tension and a porous insulating material adapted to prevent electric discharge through' said tubes as and for'the purpose described.

2. The combination with a tube or passage in which a reduced gas or vapor tension is maintained, of a mass of granular material located in the tube and adapted to allow passage of the air or gas and prevent discharge or diversion of electric energy through the gaseousbody.

3. The combination with-a vacuum tube, of an air or gas tube connected therewith and containing granular material adapted to permit the passage of gas and to prevent electric discharge therethrough.

4. The combination with a vacuum tube, of a tube connected therewith and containing porous insulatingmaterial adapted to permit the passage of gas and prevent electric discharge therethrough.

5. The combination with a vacuum tube, of a tube connected therewith and containing sand. adapted to permit the passage of gas and prevent electric discharge therethrough, as and for the purpose described.

6. The combination with a vacuum tube lamp, of a tube connected thereto .and containing sand adapted to v ermit the passage of gas and prevent electrlc discharge therethrough, as and for the purpose described.

7. A vacuum tube combined with a feed tube for feeding a gas thereto at points across which a difference of otential exists and a mass of material pervlous to the gas interposed in the feed tube, as and for the purpose described. I

8. The combination with a vacuum tube, of a gas feed tube feeding into both ends of the same and a mass of material pervious to the gas interposed in said feed tube in the path of the discharge from terminal to terminal.

9. The combination with a vacuum tube, of a gas feed tube containing granular material interposed in said feed tube in the path of the discharge through the tube whereby short-circuiting of the electric energy is prevented.

10. The combination with a vacuum tube, of a gas feed tube having branches connected to the vacuum tube at points across which a difference of potential exists and granular material interposed in one or more of said branches to prevent short-circuiting oii-the electric energy.

11. The combination with a vacuum tube, of feed tubes feeding gas into the vacuum tube at points across which a diflerence of electrical potential exists and granular material interposed in said tubes to prevent short-circuiting of the electric energy.

12. The combination with a vacuum tube, of gas feed tubes connected thereto at points 

